DecodingImageGenerator implmentation of SkImageGenerator

Source/core/platform/graphics/DecodingImageGenerator.cpp

+/*
+ * Copyright (C) 2013 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+////////////////////////////////////////////////////////////////////////////////
+#include "config.h"
+
+#include "DecodingImageGenerator.h"
+
+#include "ImageDecodingStore.h"
+#include "ImageFrameGenerator.h"
+#include "SkData.h"
+#include "platform/Logging.h"
+#include "platform/TraceEvent.h"
+#include "skia/ext/image_operations.h"
+#include "third_party/skia/src/lazy/SkDiscardablePixelRef.h"
+
+////////////////////////////////////////////////////////////////////////////////
+namespace WebCore {
+
+namespace {
+
+#ifndef NDEBUG
+inline bool operator==(const IntSize& lhs, const SkISize& rhs)
+{
+    return (lhs.width() == rhs.width()) && (lhs.height() == rhs.height());
+}
+#endif
+
+inline SkImageInfo sizeToImageInfo(const SkISize& size)
+{
+    SkImageInfo info;
+    info.fWidth = size.width();
+    info.fHeight = size.height();
+    info.fColorType = kPMColor_SkColorType;
+    info.fAlphaType = kPremul_SkAlphaType;
+    return info;
+}
+
+bool copyFrame(const SkBitmap& bitmap, void* pixels, size_t rowBytes)
+{
+    SkAutoLockPixels autoLockPixels(bitmap);
+    void* bitmapPixels = bitmap.getPixels();
+    size_t bitmapRowBytes = bitmap.rowBytes();
+    size_t bytesPerLine = bitmap.bytesPerPixel() * bitmap.width();
+    ASSERT(bytesPerLine <= rowBytes);
+    for (int row = 0; row < bitmap.height(); ++row) {
+        // This memcpy() is wasteful and bad.
+        // More refactoring should remove it.
+        memcpy(pixels, bitmapPixels, bytesPerLine);
+        pixels = static_cast<char*>(pixels) + rowBytes;
+        bitmapPixels = static_cast<char*>(bitmapPixels) + bitmapRowBytes;
+    }
+    return true;
+}
+
+} // namespace
+////////////////////////////////////////////////////////////////////////////////
+
+SkData* DecodingImageGenerator::refEncodedData()
+{
+    RefPtr<SharedBuffer> buffer = 0;
+    bool allDataReceived = false;
+    m_frameGenerator->copyData(&buffer, &allDataReceived);
+    if (buffer && allDataReceived) {
+        const void* data = static_cast<const void*>(buffer->data());
+        size_t size = buffer->size();
+        return SkData::NewWithCopy(data, size);
+    }
+    return 0;
+}
+
+bool DecodingImageGenerator::Install(PassRefPtr<ImageFrameGenerator> frameGenerator, size_t index, SkBitmap* dst)
+{
+    SkASSERT(dst);
+    DecodingImageGenerator* gen(SkNEW_ARGS(DecodingImageGenerator, (frameGenerator, index)));
+    return SkDiscardablePixelRef::Install(gen, dst);
+}
+
+DecodingImageGenerator::DecodingImageGenerator(PassRefPtr<ImageFrameGenerator> frameGenerator, size_t index)
+    : m_frameGenerator(frameGenerator)
+    , m_frameIndex(index)
+{
+}
+
+DecodingImageGenerator::~DecodingImageGenerator()
+{
+}
+
+bool DecodingImageGenerator::getInfo(SkImageInfo* info)
+{
+    ASSERT(info);
+    SkISize size = m_frameGenerator->getFullSize();
+    if ((size.width() <= 0) || (size.height() <= 0)) {
+        return false;
+    }
+    *info = sizeToImageInfo(size);
+    return true;
+}
+
+bool DecodingImageGenerator::getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes)
+{
+    if (info != sizeToImageInfo(m_frameGenerator->getFullSize())) {
+        return false;
+    }
+    RefPtr<SharedBuffer> data(0);
+    bool allDataReceived = false;
+
+    m_frameGenerator->copyData(&data, &allDataReceived);
+
+    ASSERT(data);
+
+    OwnPtr<ImageDecoder> decoder(
+        ImageDecoder::create(*data, ImageSource::AlphaPremultiplied,
+        ImageSource::GammaAndColorProfileApplied));
+    if (!decoder.get()) {
+        return false;
+    }
+    decoder->setData(data.get(), allDataReceived);
+
+    if (!decoder->isSizeAvailable()) {
+        return false;
+    }
+    ASSERT(decoder->frameSizeAtIndex(m_frameIndex)
+        == m_frameGenerator->getFullSize());
+
+    ImageFrame* frame = 0;
+    frame = decoder->frameBufferAtIndex(m_frameIndex);
+    if (frame) {
+        ASSERT(frame->getSkBitmap().width() == info.fWidth);
+        ASSERT(frame->getSkBitmap().height() == info.fHeight);
+        // FIXME: copyFrame is wasteful.
+        copyFrame(frame->getSkBitmap(), pixels, rowBytes);
+        // FIXME: find some way to convince the ImageFrameGenerator to
+        // release the memory.
+    }
+    return frame;
+}
+} // namespace WebCore